Annealing apparatus



Bes. 5, @2239 F. c. KUHNL 29382294 ANNEALING APPARATUS Filed April 25, 1938 3 Sheets-Sheet l f' @fick U Dec, 5, i939. F. c. KUHNLE, 2,182,294

ANNEALING APPARATUS Filed April 25, 1h38 3 Sheets-Sheet 5 Patented Dec. 5, 1939 emrah ystares gisant ATENE @FERIE AN NEALING APPARATUS gain Application April 25, 1938, Serial No. 204,078

1 Claim.

The present invention relates to improvements in annealing and particularly to annealing machine or apparatus wherein a rotatable rack operates in conjunction. with a highly heated furnace to successively heat a po-rtion of a tube of a plurality oi tubes continuously fed to and through said furnace by said rotatable rack; and the objects of improvement are, first, to provide an annealing apparatus that will be continuous in y its operation; second, to provide an annealing apparatus that will be particularly adapted to annealing end portions of relatively thin tubes in successive operation; third, to provide an annealing apparatus whereby nonferric metal tubes of thin section thickness can be successfully annealed to a uniform soft density for forming bends therein of small radius; fourth, to provide an apparatus for annealing nonferric metal tubes to any required degree of softness; fifth, to provide an annealing apparatus whereby one end of a tube can be heated and thereby annealed without heating to annealing temperature the opposite end of the tube; sixth, to provide an annealing apparatus that will be reliable in operation; and, seventh, to provide an annealing apparatus that will be cheap to make. These and other objects will appear from a perusal of the following description taken in connection with the accompanying drawings, in which:

Figure l is a top plan view of the herein described annealing apparatus in its entirety.

Figure 2 is a side elevation of the apparatus described, in which is shown the rotatable rack for carrying the tubes to be annealed through the annealing furnace situated above the said rack.

Figure 3 is an enlarged View of the rotatable rack drive mechanism, in which the drive clutch is in part section.

Figure 4 is a part sectional View of the heating furnace through which the tubes in the act of being annealed are carried by the rotatable rack, is taken on line V-V of Figure l, and in which is shown the piping for conducting fuel gas to the burners within the furnace.

Figure 5 is a sectional view of one of the gas burners employed, taken on the axis thereof and showing the holes through which the fuel gas iiows to the flame heating the furnace and the tubes as they are carried through the furnace bythe rotatable rack.

Figure 6 illustrates a nonferric metal tube that has been annealed and thereafter bent, and illustrates the shortness of the bend that can be made after it has been annealed by the apparatus.

Similar numerals refer to similar parts throughout the drawings. and referring thereto:

Numeral I designates the frame for supporting the several portions of the apparatus, which consists of the lower base members 2, 3, i and 5 to which are connected upright supporting members 6 having secured to their top portions, upper cross members 2a, 3d, ia and 5a. Extending between the base members 2 and ii is cross member l having secured thereto step bearing housing 8 in which is mounted a suitable bearing for supporting the vertical shaft 9 carrying the tube Supporting rack consisting of annular plate ring lll supported by lower brace members li, secured to annular plate ring Hl at their outer ends and at their inner lower ends to hub i2 on the shaft 9 and slidable longitudinally thereof; brace members I3 extending from the annular plate ring Ill to the hub M to which they are secured assist in supporting the annular plate ring It and act to steady it in its circular excursion as it revolves to feed the tubes to be annealed through the furnace. The said hubs l2 and M are adjustable longitudinally of the shaft 9 to provide for setting the rotatable rack to any desired height for heating any desired portion of the tube to be heated. At the lower end portion of the vertical shaft 9 is worm gear I5 rotatable on the vertical shaft and engaged by a worm on the shaft E6 having secured thereto gear Il driven by change speed gear i8 on adjustable stub shaft i9 carried by adjustable arm 20 carrie-d by and turnable on boss 2i extending from the side of bearing support 22 for the shaft 23 having secured thereto gear 2d, shown in broken lines in order that the adjustable arm 2l] can be clearly shown. The shaft 2S has secured to its opposite end from the gear 24, gear 25 driven by any suitable reduction speed motor as 26. The worm gear i5 has at its upper side, conical friction portion 2l engaged when the apparatus is in operation by female conical friction member 28 having extending upwardly therefrom hub 29 splined to the shaft 9 and slidable thereon by lifting bar 3d engaged by slot 3l of the hub 29 at one of its ends and by vertical rod 32 at its opposite end upon which the bar 30 is guided as it is lifted by the lifting bar 33. At the upper end of vertical rod 32 is nut 34 by which the lifter bar 3d is prevented from being raised beyond the top of the vertical rod 32. The lifting bar 33 engaging the under side of the lifter bar 30 is pivoted at 35 intermediate its ends and has at its free end, foot pedal plate 36 whereby when depressed, lifts the lifter bar 3E! and the female friction membery 28, thus disengaging the said female friction member from the conical friction member 2'! and thereby disengaging the power mechanism and allowing the rotatable rack to be stopped in its rotary excursion. 37 represents three nonferric metal tubes on the rotatable rack ready to enter the heating furnace 38 and supported by vertical columns 39 secured to the annnular plate ring i@ by upwardly extending bosses iii having a cone-like upper portion l whereby the tubes to be annealed are centered with relation to the vertical columns supported thereby.

Referring now to the heating furnace 38 of the apparatus, 42 represents the outer side plate curved to include one half of the circle scribed by the tube supporting rack, d3 the inner side plate of the furnace, Mi the end plate and 45 the fire brick lining at the inner side of the curved sides of the furnace 38, 46 the fire brick lining at the topl of the furnace and forms the cover thereof, @l the fire brick forming the bottom of the furnace and located at each side of the slot i8 through which the tubes being annealed are carried by the supporting rack on the columns 39, there being a clearance between the said tubesy and the fire brick throughout all portions of the furnace. The fire brick lining at the sides of the furnace has orifices 49 into which extendV gas burners of a lava-like composition. These burners 5G have extending longitudinally therethrough fuel delivery holes 5i and are connected to gas fuel supply pipes 52 extending over the top of the furnace where they are connected to header 53 which is connected to gas supply pipe 5d having connected thereto air and gas mixing 'valve 55 which may be of any well known make or design. Extending across from the top of the supporting frame and secured to cross members 3a and 5a is top supporting member 5t having thereon intermediate its ends upper bearing 51 supporting the upper end of the vertical shaft 9. Secured to the cross member 56 and to the upper frame cross members 2a and 5a. are furnace supporting members 58 from which is hung by bolts 59 the heating furnace 38,

Nonferric metal tubing used for forming plumbing and fountain fixtures must be sufficiently ductile that. they can be bent into curves of small radii without wrinkling the inner curved wall of the bend and the outer wall surface of the bend must be free from open grain in order to be polished to the degree required and not show through the plating which is usually of chromium of very high luster, as should there be the slightest defect in the metal caused by bending the tube that defect will show through the plating and therefore the tube will be defective. Such defects are caused by wrinkles formed at the inner side of the bend which would have to be polished out, thus weakening the tube by thinning it and by stretching and opening thegrain at the outer side of the bend. The required anneal to produce the required smooth surfaces of the tube at the inner and outer bend surfaces is important. In producing the required short bends in nonferric metal tubes, such as in brass tubes, without wrinkles or producing open grain, the tube must have the proper anneal which must be uniform in each tube and uniform throughout all the tubes forming a large number of tubes operated upon. Therefore, tubing, such as of brass, must be annealed in order that the tubing will be of uniform hardness or anneal. Therefore, after long experimentation to determine the proper density of the metal in the tubing for bending to the short bends required without wrinkling or developing open grain, the apparatus forming the subject matter of the present application was devised, whereby any degree of temperature required can be imparted to the tube for the desired anneal and a plurality of any number of tubes can be annealed each having substantially the same degree of anneal.

In the operation of the apparatus forming the subject matter of this application, fuel gas mixed with vair containing oxygen is admitted to the burners 5u through the piping 52 and header 53, where the gas is ignited, thereby heating the interior of the furnace and whatever tubes may be therein. And, as the interior of the furnace reaches the desired temperature, which has been found to be approximately thirteen hundred fifty degrees Fahrenheit for low brass tubes, the tube supporting rack carrying tubes on the columns 39 is started on its rotary excursion which carries the tubes on the said columns one after the other into and through the furnace where the tubes are progressively heated as they approach the middle zone of the furnace after which, as they approach the exit of the furnace, they begin to cool gradually until they reach the atmosphere outside the furnace where they cool rapidly until they reach the operator who removes the annealed tubes and replaces them with other tubes to be annealed.

Some metals require a higher temperature to anneal than do others. Therefore, the rate of rotation of the tube supporting rack is made changeable by exchanging the gear I8 for a gear having more or less teeth and adjusting the supporting arm 2li to the required position for proper meshing of the gears. Also, by raising the tube supporting rack on the shaft 9, any length of tube within the capacity of the apparatus may be annealed or any length of portion of the tube may be annealed and the balance of the tube left in its original density.

Having described the present invention, the rights which it is desired to secure are set forth in the following claim:

In an annealing apparatus, the combination comprising a rotatable tube supporting rack longitudinally adjustable of and secured to a vertical shaft and having a flat plate ring provided with plurality of upwardly extending columns each having a conical collar surrounding its lower end adjacent the said plate ring, the said columns being in spaced apart circular formation and a horizontally curved heating furnace in spaced apart relation above a portion only of the said plate ring and having a slot extending through its bottom and also extending the entire length of the furnace.

FREDERICK C. KUHNLE. 

